


The Experiment

by TookMeASecond



Category: Supernatural
Genre: Asphyxiation, BDSM, Bottom Dean, Dom Castiel, Enemies to Lovers, Frottage, M/M, Science, Shower Sex, Sub Dean, Top Castiel
Language: English
Status: Completed
Published: 2019-11-15
Updated: 2019-11-15
Packaged: 2021-01-31 08:48:36
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,679
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21443479
Author URL: https://archiveofourown.org/users/TookMeASecond/pseuds/TookMeASecond
Summary: Enemies Castiel and Dean are paired together in school for a science experiment. They argue though-out and miss the tutors safety tips about not touching the slimy goop that they create.In anger the slime gets thrown all over them both… A fight breaks out but they soon realise that the slime hardens and sticks. Now glued together Castiel and Dean have to take a shower together until they can get free.
Relationships: Castiel/Dean Winchester
Comments: 8
Kudos: 154





	The Experiment

**Author's Note:**

  * For [JenSpinner](https://archiveofourown.org/users/JenSpinner/gifts).

> This one has not been beta'd. My wonderful beta just sent back almost 10,000 words she meticulously went through and I am giving her a break and I wanted to post this immediately. Feel free to point out mistakes, I will try to get back in there and fix them. Just a reminder that there is a polite way to call out someone's mistakes. ;)

Castiel was thinking really hard right about now, trying to remember if he’d broken a mirror recently. Or in the past seven years. He could only attribute his recent luck to something of great magnitude. He knew his karma was alright, or at least it should have been he never really kept track but damn.

Dean probably looks about as murderous as Castiel feels, though he can’t see his face. Castiel has the other boy in a headlock, one of Dean’s arms wrapped around his waist the other gripping his thigh just above the knee. Castiel has an arm around Dean’s neck, luckily not too tight, and a hand fisted in the top of his hair.

“Well, what the fuck do we do now?” Dean asked the floor. Castiel sighed heavily, this was all Winchester’s fault. Maybe it was his karma at play.

“Where is the book? I need to see where we went wrong.”

“It’s on the desk. You know, where we had it while we were mixing the components.”

Dean’s snarky tone had Castiel arching an eyebrow and glaring down at him. He pressed his lips together in a thin line and sighed heavily as he looked toward the desk. He was relieved to see the book had missed the goo they had been flinging at each other.

Without warning Castiel tensed his arm around Dean’s neck and stalked to the other side of the room. Dean yelped and stumbled before he gained his footing as he was dragged along. Castiel couldn’t help the satisfied smile that spread his lips at the other boy’s scrambling.

“A little fucking warning next time, dude!” Castiel ignored him and tried to reach out to turn the page. “Ow! Fuck!”

Castiel barely held back a chuckle when he realized he pulled Dean’s hair trying to take his hand away from it. He supposed if they were going to be stuck together the position they were stuck in could have been worse.

“I need the page turned back one, can you reach it?” Castiel asked while scanning over the text just to make sure the answer wasn’t on this page. The hand that was around Castiel’s waist wasn’t stuck to the kid so Dean waved it around trying to feel out where the book was.

Castiel moved his hips to direct Dean’s hand, which also cause his crotch to get closer to the other boy’s face. When Dean’s fingers finally landed on the page he flicked it over and dropped his hand back down under the edge of the desk.

“This is so fucked up,” Dean said dryly. Castiel resolutely ignored him as he read over the ingredients and instructions. He sagged when he got to the safety portion at the bottom of the page. Professor Speight had gone over them in class, but that was probably when Dean had been distracting him with his grumbling about lab partners.

“Well, it says here we’re not supposed to touch the goo, it is highly adhesive. It also says it’s water soluble.” Castiel pressed his lips together and sighed again. He was already very much over today.

“Water soluble? So, like jump in a pool?” Dean asked, his voice muffled where his mouth was partially pressed to Castiel’s shirt. The other boy rolled his eyes and turned around, jerking Dean off his feet again with another squawk.

“In January? Don’t be an idiot. Does your upstairs bathroom have a shower?”

“I’m  _ not  _ getting in the shower with you, man!”

“Well, I’m not jumping in a pool,” Castiel countered cooly, “besides, I’m pretty sure you’re in a position to be doing whatever I want right now. I’m willing to bet you couldn’t stop me from getting in the shower if you tried.”

Dean had no response to that has butterflies erupted in the pit of his stomach. Why the fuck did that sound so interesting? The fact that Castiel was right had the tingling going a bit lower and Dean squeezed his thighs together in a poor attempt at stopping his cock from chubbing.

Castiel must have taken his silence for acquiescence because he then said, “Alright, Dean. I’m going to move to the door, would you open it when we get there?”

And where the fuck did that tone of voice come from? Dean was not a scared animal, he didn’t need to be coddled.

“I’m sure I can manage a door, Cas.” Castiel narrowed his eyes and tightened his arm again before swinging around, maybe a bit more forcefully than necessary and walking to Dean’s bedroom door. Dean’s own grip on Castiel’s leg tightened as well while he tried to keep his balance and keep up.

Castiel was pleased that Dean hadn’t verbally protested this time, perhaps there was hope for him yet. It wasn’t that Castiel didn’t like Dean, per say, it was just that whenever Dean opened his mouth nothing but irritating sounds came out. He had been rather attracted to him the first time he saw him, he’d been interested in getting to know Dean. Then Dean had spoken.

Dean was a brat.

The boys managed to get across the hallway to the bathroom, Dean opened both doors, Castiel kicked the bathroom door closed behind them. It was a tight fit for two eighteen year old boys but they were already squished together so it couldn’t get more awkward.

Until it did.

“Okay, so how are we doing this? Want me to get in first?” Dean asked trying to turn his head to look up at the boy holding him close. Castiel tightened his fingers in Dean’s hair to keep him from moving too much and pursed his lips together.

“Fuck! Stop that!” Dean growled out. The tone was different this time, not as much irritation. Castiel’s eyebrows hiked up his forehead and he looked down his nose at the boy bent over in front of him.

“Dean, if you get in first, how are you going to wash?”

There were a few beats of silence as Castiel allowed Dean to work the process out in his head. The hand around his waist was twisting this way and that trying to gauge a range of motion. Dean shifted on is feet a few times and pressed more into Castiel’s hip as he pulled his hand closer to his face.

“Shit.”

“Indeed. We are going to have to both get in.”

Dean cursed under his breath and sighed before trying to pull Castiel toward the tub against the wall. He didn’t have the right angle for enough leverage and Castile smiled as he held his ground, barely needing to put any effort into it. This was far more enjoyable than he’d anticipated.

“What the fuck, Cas? You just said we had to both get in.”

“Ask me nicely,” Castiel pressed using the same tone he had about the door earlier.

Dean shuffled on his feet again and wondered why the hell he didn’t have a smart ass comment on the tip of his tongue. Castiel was a goody-goody and he spoke like an encyclopedia and he still managed to look hot. Shit. Dean was still sporting a semi and the humiliation of being bossed around by Castiel Novak wasn’t helping.

“Shit, fine! Castiel, could we get in the shower and wash this stupid goo off now?” Dean tried to sound petulant, he really did. But he had a feeling he may have missed the mark.

Castiel hummed in mock thought, the vibrations carried down his chest to his stomach where Dean felt them rattle against the side of his face.

“Say please,” he coaxed, tightening his fingers just enough to cause a little bit of tension. He would have heard the bitten off groan even if Dean hadn’t not so subtly turned his face into Castiel’s shirt.

“Please,” Dean muttered lowly. Castiel smiled wickedly at himself in the mirror. He wanted so badly to press for a full sentence but figured he was already on thin ice and he would take his wins where he got them.

“Very good, Dean.” Castiel put some weight on his front foot to signal to Dean they were moving in the direction of the tub. Dean shuffled across the floor with him.

They stopped at the edge as Castiel tried to figure out the best way to do this. Dean was going to have to turn on the water, as he was the only one with a free hand. Castiel got a visual of making Dean do it with his mouth, but brushed it off as he smiled. That would probably be pushing it too far.

“Alright, I’m probably going to have to get in first, then you turn on the water and follow me in,” Castiel said surveying their position and the direction of the shower’s spray. “The water is going to take a second to warm up, which will not be pleasant, but it’s the best we can do.”

“Damn. Okay.” He rather liked a compliant Dean.

Castiel turned them and backed into the tub, he stood in the middle as Dean’s hand reach out, fingers splayed, to try and grab the handle for the water. He pulled it out from the wall and the faucet started spewing cold on their socked feet.

“You know, I could turn the temperature,” Dean mused turning the knob to the left. After a few seconds the water got warmer, then too hot.

“Too much,” Castiel said urgently picking up the foot closest to the pooling water in the tub. Dean mumbled an apology and fixed the knob. The temperature evened out and Dean pressed the button for the shower head to go on.

When the water first rained down on them there was a second of cold before it was the warm water from the faucet. Castiel backed up to the far side of the tub so Dean could get in without having water run down over his face. It sprayed his back and out the open shower and Castiel knew they’d be cleaning another mess later.

“You are very clever Dean,” he hummed happily. Dean felt his face heat up and chose not to even acknowledge the weirdness going on between them.

“Yeah, sure. So now what?”

“I think I should get my hand out of your hair. Then at least we have two hands and I have a better range of motion. This means we’ll need to get your head in the spray and it might get water on your face,” Castiel said calmly, he really believed this was the best course of action and hoped Dean wouldn’t fight him on it.

“Yeah, sure. I can hold my breath pretty long.” Castiel arched an eyebrow.

“Well, that is good to know,” he said, slightly amused.

“What the fuck-” Dean’s question was cut off when Castiel held Dean’s head tight to his stomach and stepped into the spray. The motion pressed Dean’s ass against the shower wall just above the handle and Castiel’s thigh against Dean’s crotch.

Dean sputtered water out of his mouth, but it was too late to take a deep breath. And there was absolutely no way Castiel didn’t feel his half hard dick against his leg. Dean tightened his grip on the other guy as he opened his mouth to try and suck in some air without water.

Castiel started massaging his hand against Dean’s hair, trying to get the water to soften the goo faster. When he thought he’d gotten free he tried to pull his hand away, only to tug harder than ever at Dean’s hair. He felt the twitch of Dean’s cock against his leg in the same moment Dean choked on water and tried shaking his head.

Castiel pulled them out of the spray, Dean coughing and heaving while Castiel still worked his fingers in his hair.

“I’m almost done, Dean. Just a little more?” Dean could only nod, not trusting his voice right then. Castiel waited for him to catch his breath before slowly moving back under the water, this time he carefully positioned his leg between Dean’s and bit his lip when he felt the long line of the other boy’s dick.

Dean closed his eyes and cursed his body’s reaction to what was going on. It had to be the adrenaline rush, right? He started choking on water and his adrenaline kicked up and sometimes that gets people hard, right? Whatever the hell was happening was so far off the spectrum Dean didn’t know what else to call it.

The hand in his hair finally worked itself free, but instead of Castiel pulling them out of the water his hand came down over Dean’s face and held his nose shut. Dean tried to shake his head to dislodge the fingers but Castiel’s arm tightened around his neck and he shushed him gently.

Then the leg between his started applying slow pressure and Dean’s head suddenly started spinning. Holy hell that felt fucking good. He didn’t even realize his hips were grinding forward until he heard Castiel groan above him, felt the vibrations in his ear. As soon as Dean started to struggle Castiel finally backed up and released his nose.

“What the fuck, Cas!”

“Oh, Dean. I never expected this from you. You are full of surprises,” Castiel nearly cooed above him.

“That’s just from adrenaline, or some shit! When we’re done here I am so kicking your ass!” Dean was more embarrassed than anything, but he was barely able to acknowledge that to himself, he surely wasn't going to say it.

“You have no idea do you?” Castiel asked, a slight awe in his tone. Dean wanted one of his hands free so he could punch the other guy.

“Idea about what? Get this shit off of me!”

Castiel smoothed a hand over Dean’s hair and as far down his neck and back as he could reach, then did it again. He smiled almost dopely when he felt Dean relax in his hold.

“I have learned so much about what you like in such a short amount of time.”

“Oh, my God, Cas. Shut the fuck up and lets get this shower over with.” Castiel tugged on his hair again and Dean bit out a sharp moan, then the hand was smoothed over the wet locks.

“You like it, Dean. That’s not adrenaline, or the goo, or even nerves. You are a submissive. You like being told what to do, manhandled, asphyxiation apparently,” Castiel said almost dreamily. His mind drifted a bit, pictureing how Dean would look on his knees with his hands bound behind him and a ball gag in his mouth.

Dean was suspiciously silent beneath him.

“May I show you something, Dean?” Castiel was proud he’d kept the waiver out of his voice for how shaky he felt in this moment. He was certain that if he could get Dean to accept this was real the boy would be his.

Dean’s breathing had picked up, and he shuffled his feet around again. Castiel didn’t miss him squeezing his legs together, the wet denim probably not giving him enough friction. Then in a tiny voice he said, “You’re not gonna make fun of me?”

Castiel wanted to drop to his knees right then and take Dean’s face in his hands. He cursed the fact they were still stuck in this position and he couldn’t look the other boy in the face. Dean knew, he just thought he was wrong.

“Never, Dean. I would never make fun of you for this. This is a great gift.”

  
He felt Dean sag a bit in his hold and nod his head once. Castiel wasted no time in shoving his leg back between Dean’s thighs, right up against his still hard cock. Instead of going back under the water Castiel opted to just cover Dean’s nose and mouth.

As soon as the airway was blocked he worked his leg against Dean’s crotch, hard and fast. Once Dean’s back started heaving and his grip tightened Castiel let go. He only allowed the other boy a couple breaths before his hand was back over his face. He felt Dean’s whole body tense and then the hardness against his leg kicked.

He released the grip on Dean’s nose again, this time reaching up to scratch gently through his hair. He kept his leg in motion, rubbing Dean off through his quick orgasm.

Dean’s knees felt like they were going to give out. He had never come like that before in his life, not so fast or hard. And true to his word, Castiel didn’t voice a sound of mockery. He actually comforted Dean through his turmoil and shushed his fears with gentle words.

What the fuck was going on?

Castiel turned them in the shower slowly, Dean’s legs were wobbly and he didn’t want them to fall. He worked on the goo that stuck Dean’s arm around his waist, getting it successfully cleaned off up to his shoulder.

Dean reached around and helped Castiel wash off the stuff on his stomach that had Dean’s face stuck. Once the shirt fell away Dean fell to his knees, looking up at the other boy with wonder and a bit of fear. Castiel maintained eye contact as he worked to get the hand unstuck from his knee.

Once they finally separated Dean sat back on his heels, hands on his thighs, probably completely unaware of what the position was doing to Castiel. The water temperature had dropped, but wasn’t too cold yet, and Castiel was still hard as a fucking rock.

Castiel licked his lips, Dean’s eyes tracked the motion, then fell to the tent in the khaki's right in front of his face. Dean’s tongue flicked over his bottom lip before he reached down to undo the button and zipper. He reached in cautiously and pulled out Castiel’s erection, the other boy hissing through his teeth when the cold water hit it.

“What do I do?” Dean asked. His eyes widened a bit when the cock in his hands twitched violently.

“May I try one more thing, Dean?”

At the sound of his name Dean looked up and they met eyes again. There was no more fear, and if Castiel knew what he was doing, which he did, he’d say Dean was in subspace.

Dean nodded his head slowly and waited to be told what was coming before he moved. Castiel bit his bottom lip and thanked his lucky stars. Dean was a fucking natural. Before Dean could register the movement Castiel had reached down and grabbed him by the front of his shirt.

He hauled him up and pushed him face first into the shower wall. Dean grunted on impact, but didn’t resist. Castiel plastered his chest against Dean’s back and reached around front to undo his jeans, growling in his ear the whole time.

“You have no idea, how hot you are. Had I known the whole thing was a facade you would have been mine for months now.” Dean whined at that and raised his hands to place his palms on the tile wall.

“Good boy,” Castiel ground out as he shoved Dean’s jeans off his hips. No boxers. The denim scrunched around Dean’s knees kept his legs from spreading too far, which was just fine for Castiel. He had no intention of their first time being in the shower. It would be in a bed, naked and sweaty and Dean would be fucking broken.

Instead Castiel took himself in hand and placed the tip of his uncut cock just below Dean’s ass cheeks, where his thighs met. He groaned as he pushed between them, the water and his precum the perfect lubricant for this type of fucking.

Castiel put his hands on Dean’s hips, bent his legs just slightly and started pounding into him. Dean threw his head back and cried out the first time the blunt tip hit his balls.

“I sure hope no one’s home to hear you, boy.” Dean whimpered and took a hand from the wall to cover his own mouth. Castiel chuckled and kept up his pace, slamming his hips into Dean’s ass.

“So fucking good. I’ll hardly have to train you at all.”

Dean groaned again and tensend his legs, pressing in on Castiel’s dick even harder.

“Fuck yes! So tight for me, baby.”

When he felt his balls tighten against him Castiel pulled out and took a step back, Dean whined but didn’t even have time to turn around before he was yanked from the wall by the back of his shirt and shoved up against the far one, out of the spray of water.

Castiel planted a hand in between Dean’s shoulder blades to hold him still and stripped his cock with the other hand. Dean pressed his hands and forehead to the tile wall and started a mantra of, “come on, Cas”, “do it”, “come on me”.

The last one did it for him and Castiel clenched his teeth and growled as he shot his load all over Dean’s bare ass and thighs. His skin was slightly pink from the pounding and Castiel wanted to see how much better it would look from a proper spanking.

When he was finished Dean moaned again and sank to his knees on the floor of the tub. He kept his forehead against the wall as he panted. Castiel removed his wet clothes and used the soap in the shower to wash off, then he pulled Dean to stand up and washed him as well.

After drying off they laid out the clothes in the tub and walked back across the hallway to Dean’s room.

The bathroom was a wet mess and Dean’s room was a disaster, half of it still covered in hardened goo. But Castiel decided for the both of them that it could wait. And when he’d pushed Dean into his bed, climbed in after and snuggled down under the covers Dean decided Castiel made pretty good decisions.

**Author's Note:**

> Please never deprive your partner of oxygen if you cannot see their face.


End file.
